Digital signal recording system and reproducing apparatus

Abstract

A digital signal recording system and a reproducing apparatus for reproducing signals recorded according to this recording system comprise a circuit for alternately transmitting a first digital luminance signal and a first two kinds of digital color difference signals obtained by subjecting a color picture information signal to digital pulse modulation, in terms of information of one or a plurality of scanning lines, and producing a first digital video signal having a signal format wherein signal components of two sampling points of the first digital luminance signal are arranged within the same word and signal components of the same sampling point on a picture of the first two kinds of digital color difference signals are arranged within the same word; a circuit for time-sequentially multiplexing the first digital video signal and the digital audio signals obtained by subjecting audio information signal to be recorded to digital pulse modulation, in terms of words, and recording the time-sequentially multiplexed signal onto the same one track on a recording medium; a decoder for demodulating and reproducing analog audio signals from a signal picked up and reproduced from the recording medium; and a circuit for producing an analog video signal in accordance with a standard television system, from the output first digital video signal of the decoder.

What is claimed is: 
     
       1. A digital signal recording system comprising: first producing means for independently subjecting a luminance signal and two kinds of color difference signals of a color picture information to be recorded to digital pulse modulation, to produce a first digital luminance signal and first two kinds of digital color difference signals;   second producing means for alternately transmitting said first digital luminance signal and said first two kinds of digital color difference signals in terms of information of one or a plurality of scanning lines, and producing a first digital video signal having a signal format wherein signal components of two sampling points of said first digital luminance signal are arranged within the same word and signal components of the same sampling point on a picture of said first two kinds of digital color difference signals are arranged within the same word;   third producing means for producing digital audio signals by subjecting audio signals of audio information to be recorded to digital pulse modulation; and   recording means for time-sequentially multiplexing said first digital video signal and said digital audio signals in terms of words, and recording the time-sequentially multiplexed signal onto the same one track on a recording medium.   
     
     
       2. A digital signal recording system as claimed in claim 1 in which between the signal components of the same sampling point of a picture of said first two kinds of digital color difference signals which are arranged and transmitted within the same word, one of the signal components is arranged at upper bits of the word and the other of the signal components is arranged at lower bits of the word. 
     
     
       3. A digital signal recording system as claimed in claim 1 in which a transmission period of one word of said first digital video signal is equal to a reciprocal of a sampling frequency of said digital audio signals. 
     
     
       4. A digital signal recording system as claimed in claim 1 in which said first digital video signal alternately comprises picture information of scanning lines of a first field and picture information of scanning lines of a second field, and is constituted in successive time sequence from a picture information of a top scanning line of the picture. 
     
     
       5. A digital signal recording system as claimed in claim 1 in which a number of scanning lines of the luminance signal and the color difference signals of the color picture information to be recorded is 625 lines. 
     
     
       6. A digital signal recording system as claimed in claim 1 which further comprises means for producing a second digital luminance signal obtained by subjecting said luminance signal to digital pulse modulation with a sampling frequency lower than the sampling frequency of said first digital luminance signal and a second two kinds of digital color difference signals obtained by subjecting said two kinds of color difference signals to digital pulse modulation with a sampling frequency lower than the sampling frequency of said first two kinds of digital color difference signals, means for producing a second digital video signal having an information quantity compressed to a range of several fractions of the information quantity of said first digital video signal from said second digital luminance signal and said second two kinds of digital color difference signals with a signal format similar to the signal format of said first digital video signal, and identification signal generating means for generating an identification signal in correspondence with said first and second digital video signals, said identification signal comprising at least a picture classification identification code for identifying said first and second digital video signals and a picture number identification code for identifying a recording order of the picture information from a point on the recording medium where the recording is started, said picture number identification code assuming the same value with respect to said first and second digital video signal related to the same picture information, said identification signal being added to said first and second digital video signal and recorded onto said recording medium. 
     
     
       7. A digital signal recording system as claimed in claim 6 in which said identification signal is added a plurality of times to respective beginning positions of said first and second digital video signals and recorded onto said recording medium. 
     
     
       8. A digital signal recording system as claimed in claim 6 in which said identification signal is added to respective beginning positions and terminal positions of said first and second digital video signals and recorded onto said recording medium. 
     
     
       9. A digital signal reproducing apparatus for reproducing a recording medium recorded according to the recording system claimed in claim 1, said reproducing apparatus comprising: reproducing means for picking up and reproducing recorded signals from a recording medium, said first digital video signal and said digital audio signals being time-sequentially multiplexed in terms of words and recorded on the same one track on said recording medium;   a decoder for demodulating and reproducing said digital audio signals from a reproduced signal obtained from said reproducing means, as analog audio signals;   memory means for writing said first digital video signal obtained from a part of said decoder therein, and simultaneously reading out said first digital luminance signal and said first two kinds of digital color difference signals in parallel therefrom;   a digital-to-analog converting circuit for subjecting said first digital luminance signal and said first two kinds of color difference signals from said memory means to digital-to-analog conversion to obtain the luminance signal and the two kinds of color difference signals; and   a circuit supplied with outputs of said digital-to-analog converting circuit, for producing an analog video signal in accordance with a standard television system.   
     
     
       10. A digital signal reproducing apparatus as claimed in claim 9 in which said digital-to-analog converting circuit comprises a first digital-to-analog converter for subjecting said digital luminance signal from said memory means to digital-to-analog conversion, a first switching circuit for alternately and selectively producing said first two kinds of digital color difference signals from said memory means, a second digital-to-analog converter for subjecting digital color difference signals obtained from said first switching circuit to digital-to-analog conversion, and a second switching circuit for selectively supplying a first color difference signal to a first output terminal and a second color difference signal to a second output terminal from among color difference signals obtained from said second digital-to-analog converter. 
     
     
       11. A digital signal reproducing apparatus for reproducing a recording medium recorded according to the recording system claimed in claim 6, said reproducing apparatus comprising: reproducing means for picking up and reproducing recorded signals from a recording medium, said first and second digital video signals, said digital audio signals, and said identification signals being time-sequentially multiplexed in terms of words and recorded on the same one track on said recording medium;   a decoder for demodulating and reproducing said digital audio signals from a reproduced signal obtained from said reproducing means, as analog audio signals;   memory means for writing said first or second digital video signal obtained from a part of said decoder therein, and simultaneously reading out said first or second digital luminance signal and said first or second two kinds of digital color difference signals in parallel therefrom;   memory write-in control means for discriminating said identification signal from the reproduced signal obtained from said reproducing means, and interrupting write-in of the reproduced second digital video signal into said memory means to successively write a reproduced digital video signal of a different picture number into said memory means, only when a value of the picture number identification code within said discriminated identification signal is equal to a value of a picture number identification code within an identification code discriminated immediately prior thereto and it is discriminated from the picture classification identification code that the reproduced digital video signal is said second digital video signal;   a digital-to-analog converting circuit for subjecting said first or second digital luminance signal and said first or second two kinds of color difference signals read out from said memory means to digital-to- analog conversion to obtain the luminance signal and the two kinds of color difference signals; and   a circuit supplied with outputs of said digital-to-analog converting circuit, for producing an analog video signal in accordance with a standard television system.